What is 'living life in the spirit'?

Does this mean fruits of the spirit, like humility, peace, love, and joy, or our actions like sharing with those in need?

Romans 8:5

AMP - 5 For those who are according to the flesh and are controlled by its unholy desires set their minds on and pursue those things which gratify the flesh, but those who are according to the Spirit and are controlled by the desires of the Spirit set their minds on and seek those things which gratify the [Holy] Spirit.

I think that Paul addresses this question specifically in Galatians 5:16-26, when he discusses the deeds and attitudes that characterize walking "according to the flesh" in verses 19-21 and 26, although I would say that Paul's list in that regard is intended to provide examples, rather than to be all-inclusive. That is, there are other forms of sin or of gratifying the fleshly nature besides the ones that he lists.
Then, in verses 22-23, he lists (as mentioned by the questioner) the fruits of the Spirit, which I would describe as attitudes rather than concrete or specific actions. But a person who possesses those attitudes, and who then "walks by the Spirit" (that is, who, with the help of the Holy Spirit, conducts himself according to those attitudes) will, as a result, perform deeds such as sharing with those in need, or other concrete actions that show or witness to that person's love for both God and others. And (as Paul said in verse 15) such love is the fulfilling of the Law.